Mohapatra Saswat S, Ramachandran Dhanya, Mantri Chinmay K, Colwell Rita R, Singh Durg V
Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar 751023, India.
Res Microbiol. 2009 Jan-Feb;160(1):57-62. doi: 10.1016/j.resmic.2008.10.008. Epub 2008 Nov 5.
Sequencing of three housekeeping genes, mdh, dnaE and recA, and ribotyping for seven non-toxigenic Vibrio cholerae O1 strains isolated from different geographic sources indicate a phylogenetic relationship among the strains. Results of MLST and ribotyping indicate a clear difference between three toxigenic strains (N16961, O395, and 569B) and three non-toxigenic strains from India (GS1, GS2, and GW87) and one Guam strain (X392), the latter of which were similar in both MLST and ribotyping, while two other non-toxigenic strains from the USA and India (2740-80 and OR69) appeared to be more closely related to toxigenic strains than to non-toxigenic strains, although this was not supported by ribotyping. These results provide clues to the emergence of toxigenic strains from a non-toxigenic progenitor by acquisition of virulence gene clusters. Results of split decomposition analysis suggest that widespread recombination occurs among the three housekeeping genes and that recombination plays an important role in the emergence of toxigenic strains of V. cholerae O1.
对从不同地理来源分离出的7株非产毒霍乱弧菌O1菌株的3个管家基因mdh、dnaE和recA进行测序以及核糖体分型，结果表明这些菌株之间存在系统发育关系。多位点序列分型（MLST）和核糖体分型结果显示，3株产毒菌株（N16961、O395和569B）与来自印度的3株非产毒菌株（GS1、GS2和GW87）以及1株关岛菌株（X392）之间存在明显差异，后一组菌株在MLST和核糖体分型方面均相似，而另外两株分别来自美国和印度的非产毒菌株（2740 - 80和OR69）与产毒菌株的关系似乎比与非产毒菌株的关系更为密切，尽管核糖体分型并不支持这一点。这些结果为产毒菌株通过获得毒力基因簇从非产毒祖先进化而来提供了线索。分裂分解分析结果表明，3个管家基因之间广泛发生重组，且重组在霍乱弧菌O1产毒菌株的出现过程中起重要作用。
